SED1374 Datasheet, PDF (89/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

Epson Research and Development
Vancouver Design Center
Page 81
12.2 Alternate SwivelView Mode
Alternate SwivelView Mode may be used when the virtual image size of Default
SwivelView Mode cannot be contained in the 40kByte integrated frame buffer. For
example, the panel size is 240x160 and the display mode is 8 bit-per-pixel. The minimum
virtual image size for Default SwivelView Mode would be 240x256 which requires 60K
bytes. Alternate SwivelView Mode requires a panel size of only 240x160 which needs only
38,400 bytes.
Alternate SwivelView Mode requires the memory clock (MCLK) to be at least twice the
frequency of the pixel clock (PCLK), i.e. MCLK ≥ 2 x PCLK. Because of this, the power
consumption in Alternate SwivelView Mode is higher than in Default SwivelView Mode.
The following figure shows how the programmer sees a 240x160 image and how the image
is being displayed. The application image is written to the SED1374 in the following sense:
A–B–C–D. The display is refreshed by the SED1374 in the following sense: B-D-A-C.
physical
memory
start
address
A
B
SwivelView
window
C
D
160
image seen by programmer
= image in display buffer
display
start
address
240
image refreshed by SED1374
Figure 12-2: Relationship Between The Screen Image and the Image Refreshed by SED1374
Hardware Functional Specification
Issue Date: 99/04/29
SED1374
X26A-A-001-02